Least Weasel
The least weasel (Mustela nivalis) is the smallest member of the Mustelidae (as well as the smallest of the Carnivora), native to Eurasia, North America and North Africa, though it has been introduced elsewhere. It is classed as Least Concern by the IUCN, due to its wide distribution and presumably large population.Despite its small size, the least weasel is a fierce hunter, capable of killing a rabbit 5-10 times its own weight. The least weasel has a thin, greatly elongated and extremely flexible body with a small, yet elongated, blunt muzzled head which is no thicker than the neck. The eyes are large, bulging and dark coloured. The legs and tail are relatively short, the latter constituting less than half its body length. The feet are armed with sharp, dark claws, and the soles are heavily haired. The skull, especially that of the small rixosa group, has an infantile appearance when compared with that of other members of the genus Mustela (in particular, the stoat and kolonok). This is expressed in the relatively large size of the cranium and shortened facial region. The skull is, overall, similar to that of the stoat, but smaller, though the skulls of large male weasels tend to overlap in size with those of small female stoats. The winter fur is dense, but short and closely fitting. In northern subspecies, the fur is soft and silky, but coarse in southern forms. The summer fur is very short, sparser and rougher. The upper parts in the summer fur are dark, but vary geographically from dark-tawny or dark-chocolate to light pale tawny or sandy. The lower parts, including the lower jaw and inner sides of the legs are white. The dividing line between the dark upper and light lower parts is straight, but sometimes forms an irregular line. In winter, the fur is pure white, and only exhibits black hairs in rare circumstances. The least weasel has a typical Mustelid territorial pattern, consisting of exclusive male ranges encompassing multiple female ranges. The population density of each territory depends greatly on food supply and reproductive success, thus the social structure and population density of any given territory is unstable and flexible. Like the stoat, the male least weasel extends its range during spring or during food shortages. Its scent marking behaviour is similar to the stoat's; it uses faeces, urine and anal and dermal gland secretions, the latter two of which are deposited by anal dragging and body rubbing. The least weasel does not dig its own dens, but nest in the abandoned burrows of other species such as moles and rats. The burrow entrance measures about 2.5 cm across and leads to the nest chamber located up to 15 cm below-ground. The nest chamber (which is used for sleeping, rearing kits and storing food) measures 10 cm in diametre, and is lined with straw and the skins of the weasel's prey. The least weasel is small enough to be preyed upon by a range of other predators. Least weasel remains have been found in the excrement of red foxes, sables, steppe and forest polecat, stoats, eagle owls and buzzards. The owls most efficient at capturing least weasels are barn, barred and great horned owls. Other birds of prey threatening to the least weasel include broad-winged and rough-legged buzzards. Some snake species may prey on the least weasel, including the black rat snake and copperhead.[23] Aside from its smaller size, the least weasel is more vulnerable to predation than the stoat because it lacks a black predator deflection mark on the tail. In areas where the least weasel is sympatric with the stoat, the two species compete with each other for rodent prey. The weasel manages to avoid overly competing with the stoat by living in more upland areas, and preying on smaller prey and being capable of entering smaller holes. The least weasel actively avoids encounters with stoats, though female weasels are less likely to stop foraging in the presence of stoats, likely because their smaller size allows them to quickly escape in holes. Category:Animals Category:Mammals Category:Mustelids Category:Carnivores Category:Grassland animals Category:Vertebrates Category:North American Animals Category:Asian Animals Category:African Animals Category:European Animals